\begin{tabbing}
last{-}solution(${\it es}$;$P$;$d$)($e$)
\\[0ex]$\,\equiv$$_{\mbox{\scriptsize def}}$$\;\;$\=case TERMOF\{last{-}event:ObjectId, 1:l, i:l\}(${\it es}$,$e$,$P$,$d$)\+
\\[0ex]o\=f inl($x$) =$>$ inr $\cdot$ \+
\\[0ex]$\mid$ inr($p$) =$>$ inl ($p$.1) 
\-\-
\end{tabbing}